本文提出六相永磁式同步電動機轉速控制系統之設計，系統不需額外的電流回授裝置，故可降低硬體成本。在轉速閉迴路控制中，用轉矩命令推導每相的電流命令，不僅可以作交軸電壓命令的計算，亦可補償直軸電壓命令，以提高運轉效率。文中採用兩組三相變頻器之電壓空間向量脈波調變控制，可提高直流電壓使用率，且使六相永磁式同步電動機具有弦式電流響應，以減少電磁轉矩鏈波成分。
本文採用32位元的數位控制器(DSP, TMS320F28035)完成實體製作，控制軟體使用C語言編寫。本文已完成1000 rpm，375 W功率轉換系統之製作。實測結果顯示轉速誤差為2 rpm。每組三相獨立運轉時其電流峰值為17.1 A，採用本文的轉速閉迴路控制直軸電壓補償，電動機相電流的峰值降至4.4 A，電流諧波含量為4.30 %。由實測結果可驗證控制策略之可行性。

This thesis presents the design of speed control system for six-phase permanent-magnet synchronous motors (PMSM). This system requires no additional current feedback device, resulting in the reduction of hardware costs. In the closed-loop control of motor speed, the torque command can be used to derive the current command for each phase, to facilitate the calculation of the q-axis voltage command as well as compensation of the d-axis voltage command for efficiency improvement. Meanwhile, two sets of three-phase inverter with voltage space vector pulse-width modulation, are designed to increase the utilization rate of the dc voltage, and provide sinusoidal current response for reducing torque ripple of PMSM.
The 32-bit digital signal processor, TMS320F28035, is adopted to implement the control functions of the system with C language. A prototype of 1000 rpm and 375 W power conversion system is built. The error of speed is 2 rpm. Operating the two three-phase inverters independently yields a current peak value of 17.1 A. The current peak value is reduced to 4.4A when the aforementioned compensation of d-axis voltage command under closed-loop control of motor speed is introduced. The corresponding total harmonic distortion of current is 4.30 %. The feasibility of the proposed system is verified experimentally.

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